Concept:Fluvial processes, especially the erosive action of a river, produce several characteristic landforms.
Explanation:Rivers erode their beds and banks mainly by mechanical processes.
Abrasion, also called corrasion, occurs when rock fragments carried by the river scrape and wear away the channel bed and banks.
Attrition happens when the transported sediment particles collide with one another and break into smaller, smoother pieces.
Another process, hydraulic action, results from the force of moving water entering cracks in the river bank.
Solution, or corrosion, removes soluble minerals from the channel floor and sides.
Together these processes form features such as gorges, rapids, waterfall plunge pools, and interlocking spurs.
These landforms are therefore directly linked to river erosion rather than to deposition or wind action.
Answer:A. River erosion